Field of the Invention
This invention pertains to the use of liquid color in plastic molding and extrusion. The patent application even more specifically pertains to a quarter turn adapter connector preferably, but not necessarily, utilized with a liquid color pump which may be installed on or form a part of the lid of a liquid color container.
Description of the Prior Art
Pumps for liquid color are known, with one such pump being disclosed in U.S. Pat. No. 7,416,096, with another being disclosed in U.S. Pat. No. 7,980,834, and yet another being disclosed in U.S. Pat. No. 8,800,821. The disclosures of the '096, '834, and '821 patents are incorporated by reference.
The '096 patent discloses a container of liquid color material having a diaphragm liquid color pump located in the container for providing liquid color from the container. The diaphragm liquid color pump is located in the container at the container bottom, where the pump can collect liquid color as the container empties. The pump is driven by a pneumatic piston-cylinder combination located outside the container, with a shaft extending downwardly from the pneumatic piston-cylinder combination to the diaphragm pump, to reciprocate the diaphragm back and forth to effectuate pumping action.
The apparatus disclosed in the '096 patent is relatively low in cost. The apparatus includes a liquid-tight fitting allowing the liquid color output from the pump to be supplied directly to a plastics material processing machine, for the liquid color to impart color directly to plastic parts as they are manufactured.
The apparatus disclosed in the '834 patent provides pressure boosting, permitting liquid color to be injected into an extruder screw or a molding machine screw barrel at a position downstream from the throat, closer to the position at which the finished plastic parts are molded or extruded.
The '821 patent discloses a disposable low-cost pump in a container for liquid color, where the pump is fabricated from a plurality of PVC tubular members connected in a way to provide a pumping chamber. A piston is displaceable into the pumping chamber. A spring biases the piston outwardly from the chamber, in opposition to force applied by an air cylinder.
While these devices have merit and have proved commercially successful, there is a continuing need for lower cost, higher reliability apparatus to provide liquid color from liquid color containers to injection and compression molding machines and to extruders, to color plastic parts in the course of manufacture thereof.
While disposable pumps for liquid color are known in the sense that those pumps can be removed from the liquid color containers and discarded, there is a need for a pump that fits integrally with a liquid color container in a manner to be a part of the container so that the complete assembled pump cannot be removed without compromising the container and leaving an open hole. This is to discourage pump scavenging. There is a further need in practice, which is somewhat inconsistent with the foregoing in practice, for the relatively high cost portions of the pump to be easily and quickly removable once the container has been emptied, so that those high cost portions of the pump may be used with a new, full container of liquid color, while low cost portions of the pump remain with an empty container to prevent flow of any remaining liquid color out of the container, so that these low cost portions of the pump may be used when the container is refilled and the pump is reassembled to pump liquid color from the new container. Many but not all of these needs are satisfied by the apparatus disclosed in the '375 application, of which this application is a continuation-in-part.